Field of the Invention
The field of the present application pertains to medical devices. More specifically, the present application is related to devices and methods for removal of thromboembolic obstructing matter from the human endovascular system, including cerebral arteries and other parts of the human body.
Description of the Prior Art
Arterial and venous thromboembolic disease remains a major cause of death and disability despite the discovery of heparin by McLean and Howell in 1916 and its subsequent introduction into clinical practice in 1936. Each year, acute limb ischemia affects 14 persons per 100,000 in the United States population, with procedures relating to the treatment of acute arterial ischemia comprising 10% to 14% of the annual vascular surgical workload. Venous thromboembolism occurs at a fivefold greater frequency with recent estimates of 77.6 cases per 100,000 person-years.
Strokes may be caused by a rupture or bleeding of a cerebral artery (“hemorrhagic stroke”), or a blockage in a cerebral artery due to a thromboembolism (“ischemic stroke”). Intracerebral hemorrhage (ICH) bleeding accounts for approximately 10-12% of all stroke cases in the United States. ICH has long been associated with high rates of morbidity and mortality. Treatment choices for ICH are limited, and the effectiveness of currently available therapies is inadequate. Thrombolytics alone are not recommended, but are currently being investigated for use in conjunction with aspiration and other surgical techniques.
While intracranial hemorrhage is caused by blood clots located outside the blood vessels in the brain, Acute Ischemic Stroke (AIS) is caused by blood clots blocking a blood vessel in the brain arteries. AIS is the third leading cause of death in the United States. Each year, approximately 700,000 people suffer an Acute Ischemic Stroke, and more than 100,000 people die each year in the United States. Nearly three-quarters of all these strokes occur in people over the age of 65. The risk of having a stroke more than doubles each decade after the age of 55. According to the World Health Organization, more than 12 million people suffer Acute Ischemic Stroke worldwide each year. Of these, more than 4 million die and another 4 million are permanently disabled.
Endovascular and outside of endovascular thromboembolic disease remain very widespread causes of death and disability with no ideally effective treatment currently available. Thus, there is a significant need for improved devices, methods and systems for treating thromboembolic disease.
There are many approaches for removing thromboembolic material from the body, either surgical or using catheter devices for endovascular and outside endovascular removal of obstructive matter, such as blood clots, thrombus, atheroma, plaque and the like. These techniques are related to rotating baskets or impellers, cutters, high pressure fluid injections, Archimedes screw, vacuum, rotating wires and other means as described in U.S. Pat. Nos. 4,732,154; 4,737,153; 4,771,774; 4,886,490; 4,883,458; 4,923,462; 4,966,604; 5,041,082; 5,047,040; 5,135,531; 5,180,376; 5,226,909; 5,334,211; 5,376,100; 5,443,443; 5,462,529; 5,485,042; 5,501,694; 5,556,408; 5,569,275; 5,630,806; 5,653,696; 5,695,507; 5,766,191; 5,795,322; 5,843,031; 5,873,882; 5,876,414; 5,911,734; 5,947,940; 5,972,019; 7,037,316; 7,179,269; 7,235,088; 7,666,161; 7,763,010; 7,842,006; 7,842,055; 7,938,820; 7,942,852; 8,062,317; 8,414,543; 8,414,543; 8,535,290 and 8,545,447; and US Applications Nos., 2014/0324080 and 2014/0330286.
Removal of thromboembolic material and blood clots from brain arteries are described in the following U.S. Pat. Nos. 7,063,707; 7,316,692; 7,931,659; 833,796; 8,366,735; 8,460,312; 8,366,735; 8,784,441; 8,801,748, 8,814,892, as well as Simon S. et al., “Exploring the efficacy of cyclic vs. static aspiration in cerebral thrombectomy model: an initial proof of concept study”, Journal of Neurointerventional Surgery 2014 November; 6(9): 677-83; among others. Devices and methods disclosed in the prior art include several devices and methods such as: embolectomy devices, clot pullers, retrieving devices or separating devices with aspiration. While most of these devices are capable of removing blood clots from the human arteries, there is still a clinical need for a simple, quick and easy access with devices to the treatment site through tortuous brain arteries, and safe removal of blood clots in a single pass. Often, catheters used to remove clots from brain arteries get clogged after partial removal of clots even under absolute vacuum. In such situations, physicians typically use a “corking” approach to grab the clot with a vacuum and then remove the clogged catheter outside the body to remove the clot. Next they clean the clots from the catheter and navigate the catheter back up to the targeted occlusion to remove the remaining clot. Risks related with device manipulations and multiple accessing of the treatment site, as well as the extended time required for removing blood clots from arteries, may lead to another stroke and have a crucial impact on short and long term clinical outcomes. Thus, there is a need for more efficient and effective devices that facilitate a quick and single pass for the removal of thromboembolic material.